A small, portable minicomputer (PDP 11/03) has been ordered to facilitate expanding our studies into clinical areas. Delivery is expected early in 1979. Several months will be required to develop appropriate programs for on-line use. We plan to carry out experiments in dogs to produce a chemical lung injury in order to make quantitative comparisons between the non-invasive measurement of pulmonary tissue volume (Vtiss), pulmonary capillary blood flow (Qc), functional residual capacity (FRC) and pulmonary diffusing capacity (DLCO), and actual lung tissue weight and morphology as a response to the injury. These experiments will employ extensive invasive monitoring of a wide spectrum of cardio-respiratory variables. Later in the year, we plan to begin clinical studies, initially in patients in the operating room. Before any such studies are begun the protocols and informed consent procedures will be reviewed by the Clinical Investigation Committee, and the registry numbers for the protocols will be communicated to the NIGMS Program Director. Clinical experience at present suggests that several clinical situations should be studied: major surgery requiring considerable infusion of fluids and/or transfusion of blood e.g., abdominal aortic aneurysm; specific hemodilution techniques e.g., Harrington rod procedures for correction of severe spinal scoliosis; severe multi-system trauma; patients with normal pulmonary ventilation/perfusion distribution undergoing open heart surgery requiring cardio-pulmonary bypass to study so-called "post-pump lung". Before we undertake any of these studies we plan to review all our results to date.